01664220

Component

Developing new Safety Performance Functions (SPF) can improve the accuracy of the results of the Highway Safety Manual (HSM) methodologies. In this study, local SPFs were developed for rural four-lane divided highway segments in Kansas. Crash predictions from newly developed SPFs were compared to the HSM-given SPF and modified SPFs with updated coefficients. Using Negative Binomial regression, the most suitable model for local conditions was developed. Several additional variables were considered and tested in the new SPFs, which were run through a validation set of locations to confirm accuracy. Comparison of the new SPF with HSM-given SPF and modified SPF led to the conclusion that the newly developed Kansas-specific SPF for four-lane divided rural highway segments reliably predicts total crashes and fatal and injury crashes in rural Kansas. The Kansas-specific SPFs are capable of more accurately predicting total crashes and fatal and injury crashes on multilane segments compared to the HSM and the modified HSM models.

This paper was sponsored by TRB committee ANB25 Standing Committee on Highway Safety Performance.

18-03147

English

4p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

References

Divided highways; Four lane highways; Rural highways

Highway Safety Manual

Crash prediction models; Local data; Negative binomial regression; Safety performance functions

Kansas

Highways; Safety and Human Factors

Transportation Research Board Annual Meeting 2018 Paper #18-03147

TRIS, TRB, ATRI

Jan 8 2018 10:46AM